1 /*
2  *  freebsd ELF definitions
3  *
4  *  Copyright (c) 2013-15 Stacey D. Son
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #ifndef TARGET_OS_ELF_H
21 #define TARGET_OS_ELF_H
22 
23 #include "target_arch_elf.h"
24 #include "elf.h"
25 
26 #define bsd_get_ncpu() 1 /* until we pull in bsd-proc.[hc] */
27 
28 /* this flag is uneffective under linux too, should be deleted */
29 #ifndef MAP_DENYWRITE
30 #define MAP_DENYWRITE 0
31 #endif
32 
33 /* should probably go in elf.h */
34 #ifndef ELIBBAD
35 #define ELIBBAD 80
36 #endif
37 
38 #ifndef ELF_PLATFORM
39 #define ELF_PLATFORM (NULL)
40 #endif
41 
42 /* XXX Look at the other conflicting AT_* values. */
43 #define FREEBSD_AT_NCPUS     19
44 #define FREEBSD_AT_HWCAP     25
45 #define FREEBSD_AT_HWCAP2    26
46 
47 #ifdef TARGET_ABI32
48 #undef ELF_CLASS
49 #define ELF_CLASS ELFCLASS32
50 #undef bswaptls
51 #define bswaptls(ptr) bswap32s(ptr)
52 #endif
53 
54 /* max code+data+bss space allocated to elf interpreter */
55 #define INTERP_MAP_SIZE (32 * 1024 * 1024)
56 
57 /* max code+data+bss+brk space allocated to ET_DYN executables */
58 #define ET_DYN_MAP_SIZE (128 * 1024 * 1024)
59 
60 /* Necessary parameters */
61 #define TARGET_ELF_EXEC_PAGESIZE TARGET_PAGE_SIZE
62 #define TARGET_ELF_PAGESTART(_v) ((_v) & \
63         ~(unsigned long)(TARGET_ELF_EXEC_PAGESIZE - 1))
64 #define TARGET_ELF_PAGEOFFSET(_v) ((_v) & (TARGET_ELF_EXEC_PAGESIZE - 1))
65 
66 #define DLINFO_ITEMS 14
67 
68 static abi_ulong target_create_elf_tables(abi_ulong p, int argc, int envc,
69                                           abi_ulong stringp,
70                                           struct elfhdr *exec,
71                                           abi_ulong load_addr,
72                                           abi_ulong load_bias,
73                                           abi_ulong interp_load_addr,
74                                           struct image_info *info)
75 {
76         abi_ulong features, sp;
77         int size;
78         const int n = sizeof(elf_addr_t);
79 
80         target_auxents_sz = 0;
81         sp = p;
82         /*
83          * Force 16 byte _final_ alignment here for generality.
84          */
85         sp = sp & ~(abi_ulong)15;
86         size = (DLINFO_ITEMS + 1) * 2;
87         size += envc + argc + 2;
88         size += 1;                      /* argc itself */
89         size *= n;
90         if (size & 15) {
91             sp -= 16 - (size & 15);
92         }
93 
94         /*
95          * FreeBSD defines elf_addr_t as Elf32_Off / Elf64_Off
96          */
97 #define NEW_AUX_ENT(id, val) do {               \
98             sp -= n; put_user_ual(val, sp);     \
99             sp -= n; put_user_ual(id, sp);      \
100             target_auxents_sz += 2 * n;         \
101           } while (0)
102 
103         NEW_AUX_ENT(AT_NULL, 0);
104 
105         /* There must be exactly DLINFO_ITEMS entries here.  */
106         NEW_AUX_ENT(AT_PHDR, (abi_ulong)(load_addr + exec->e_phoff));
107         NEW_AUX_ENT(AT_PHENT, (abi_ulong)(sizeof(struct elf_phdr)));
108         NEW_AUX_ENT(AT_PHNUM, (abi_ulong)(exec->e_phnum));
109         NEW_AUX_ENT(AT_PAGESZ, (abi_ulong)(TARGET_PAGE_SIZE));
110         NEW_AUX_ENT(AT_BASE, (abi_ulong)(interp_load_addr));
111         NEW_AUX_ENT(AT_FLAGS, (abi_ulong)0);
112         NEW_AUX_ENT(FREEBSD_AT_NCPUS, (abi_ulong)bsd_get_ncpu());
113         NEW_AUX_ENT(AT_ENTRY, load_bias + exec->e_entry);
114         features = ELF_HWCAP;
115         NEW_AUX_ENT(FREEBSD_AT_HWCAP, features);
116 #ifdef ELF_HWCAP2
117         features = ELF_HWCAP2;
118         NEW_AUX_ENT(FREEBSD_AT_HWCAP2, features);
119 #endif
120         NEW_AUX_ENT(AT_UID, (abi_ulong)getuid());
121         NEW_AUX_ENT(AT_EUID, (abi_ulong)geteuid());
122         NEW_AUX_ENT(AT_GID, (abi_ulong)getgid());
123         NEW_AUX_ENT(AT_EGID, (abi_ulong)getegid());
124         target_auxents = sp; /* Note where the aux entries are in the target */
125 #ifdef ARCH_DLINFO
126         /*
127          * ARCH_DLINFO must come last so platform specific code can enforce
128          * special alignment requirements on the AUXV if necessary (eg. PPC).
129          */
130         ARCH_DLINFO;
131 #endif
132 #undef NEW_AUX_ENT
133 
134         sp = loader_build_argptr(envc, argc, sp, stringp);
135         return sp;
136 }
137 
138 #endif /* TARGET_OS_ELF_H */
139